Railway brake discs



April 18, 1967 G. A. PELIKAN RAILWAY BRAKE DISCS 3 Sheets-Sheet 1 Filed April 16, 1965 N m m W w m m 5 April 18, 1967 A. PELIKAN RAILWAY BRAKE DISCS 5 Sheets-Sheet 2 Filed April 16, 1965 April 18, 1967 GJA. PELIKAN RAILWAY BRAKE DISCS 5 Sheets-Sheet 5 Filed April 16, 1965 INVENTOR 5202px ,4 pfZ/K/IA/ BY 6 TroR EY6/ United States Patent Office 3,314,5 09 Patented Apr. 18, 1967 3,314,509 RAILWAY BRAKE DISCS George A. Pelikan, Closter, N.J., assignor to Buffalo Brake Beam Company, a corporation of New York Filed Apr. 16, 1965, Ser. No. 448,781 6 Claims. (Cl. 188218) The present invention relates to disc brakes for railway car wheels and is an improvement on the type of railway brake discs disclosed in Busch US. Patent No. 2,869,688.

The conventional railway freight car has two trucks, each with side frames and four wheels arranged into two sets of coaxial wheels on two axles supported on said side frames. It has been proposed to provide brake mechanisms in connection with these wheels having rotor brake discs rigid with said wheels and to apply the brakes on the brake faces of said .brake discs. Brake mechanisms of this general type are described, for example, in Busch Patents No. 2,903,096, No. 2,903,097 and No. 2,903,098.

In connection with the brake mechanism described, the brake discs have on the sides thereof opposite their brake faces a series of radially extending fins to dissipate the heat generated on the discs from the brake shoes applied thereto during braking actions.

In cases where the railway cars are subjected to frequent braking actions at short intervals, the brake discs may become overheated.

One object of the present invention is to provide a new and improved railway brake disc designed to cool the discs quickly while rotating.

Another object of the present invention is to provide a new and improved railway brake disc designed to cool the discs quickly in the intervals between braking actions in either direction of rotation of the discs.

As a feature of the present invention, the heat dissipating fins of the brake disc, instead of extending in a radial direction, as previously proposed, extend curvedly in a direction to induce circulation of air across the finned face of the brake side as the brake disc rotates in one direction. As a further feature of the present invention, the fins are made up of two groups, the fins of the two groups being curvedly designed, so that one group goes into action to induce the circulation of air across the finned face of the brake disc when rotating in one direction and the other group goes into action to induce circulation of air across the finned face of the brake disc when rotating in the other direction. The fins thereby serve not only as heat dissipating elements but also serve as circulation inducing vanes to cool the brake discs more effectively in the intervals between braking actions, regardless of the direction of movement of the railway car.

Another object of the present invention is to provide a new and improved brake disc, made of a plurality of segments and designed to aiford mutual support against braking action applied to any one of these segments.

As another feature of the present invention, the brake disc comprises a plurality of similar segments having means for quickly and easily interconnecting or disconnecting them, these interconnecting means being designed to cause any axial braking pressure applied directly to any one of these segments to be directly transmitted to and thereby directly resisted by the adjacent segment or segments. These brake disc segments are also designed to be interlocked against relative axial displacement or relative angular displacement about any diametrical axis, upon application of axial braking pressure on any one segment.

Various other objects, features and advantages of the present invention are apparent from the following description and from the accompanying drawings, in which FIG. 1 is a top plan view of a part of a railway freight car truck, showing a brake mechanism with a friction brake disc embodying the present invention;

FIG. 2 is a face view of the finned side of the brake disc shown with complemental segmental sections separated in preparation for assembly on the wheels of the railway car truck;

FIG. 3 is a face View of part of the finned side of the brake disc shown in FIG. 2 but on a larger scale and shows the complemental segmental sections of the disc secured together;

FIG. 4 is a section of the brake disc taken on lines 44 of FIG. 3;

FIG. 5 is an exploded fragmentary view of two brake disc segments, shown prior to assembly;

FIG. 6 is a section of the brake disc taken on lines 66 of FIG. 3; and

FIG. 7 is a section of the brake disc taken on lines 77 of FIG. 3.

Referring to the drawings, the friction brake disc of the present invention is shown, for purposes of illustration, applied to a railway freight car truck having brake mechanisms of the general type shown in Busch No. 2,903,096, but it must be understood that the present invention is not limited thereto. In the specific embodiment of the brake mechanism illustrated, the railway freight car truck comprises a pair of side frames 10, a truck bolster 11 on which the car body (not shown) is mounted, extending between said side frames and springsupported on said side frames, and a pair of parallel axles 12 (only one being shown), extending between the side frames and journailed in said side frames. Each of these axles 12 carries a pair of car wheels 13 near its opposite ends for riding engagement with rails 14 (only one being shown). The car truck described is of conventional well-known construction and is more fully described and shown in the aforesaid Busch Patent No. 2,903,096.

Secured to each wheel 13 on its inboard side is a friction disc 15, forming with said wheel a coaxial wheel and brake disc unit 16 and constituting part of a disc brake deviceto be described. The braking mechanism, per

' se, for applying braking shoes to the friction brake discs 15, is the subject-matter of the aforesaid Busch Patent No. 2,903,096. This braking mechanism for each car truck comprises four L-shaped brake head levers 17 (only one being shown), arranged two on one side of the bolster 11 for two coaxial wheel and disc units 16 on this side of the bolster and two on the other side of the bolster for the other two coaxial wheel and brake disc units. Each of these brake head levers 17 is pivotally secured at one end 18 to a bracket 19 rigidly ailixed to a corresponding side frame and projecting laterally therefrom. The other end of the brake head lever 17 has a brake head 20 carrying a segmental brake shoe 21. Each brake head lever 17 is thereby supported to move substantially in a horizontal plane about its pivot support at 18 into braking position to apply the brake shoe 21 to the friction face on the brake disc 15 and out of braking position, and the brake shoe has a yieldable connection 22 with the brake head, allowing said brake head to rock and thereby to align the brake shoe automatically into continuous face braking contact with the braking face of the disc, upon the application of the brakes.

Power is applied to the four brake head levers 17 simultaneously through a bridle beam 24 extending on one side of the bolster 11 horizontally across the center line of the car truck with its middle region substantially on said center line. The intermediate section of the beam 24 is supported from the car body by a lever (not shown) power-actuated by a pull rod (not shown) from a source of power, as for example, an air cylinder (not shown).

Power is transmitted from the bridle beam 24 simultaneously to the two brake head levers 17 on one side of the bolster 11 by means of brake arms 25 (only one being shown), each pivotally supported at 26 to the elbow 27 of the corresponding brake head lever and having a pivotal connection at one end 28, with the corresponding end of the bridle beam 24 through a flexible connection 29. For transmitting power from the brake arms 25 on one side of the bolster 11 to the brake head levers 17 on the opposite side, there are provided two brake arms (not shown) pivoted intermediate their ends to the elbows of the respective brake head levers on said opposite side of the bolster and fulcrumed at one end to brackets (not shown) affixed to the side of the bolster. The latter brake arms so fulcrumed, are operated from the brake arms 25 by push rods 39 (only one being shown), each passing through the bolster 11 and pivotally connected at its ends to a pair of said brake arms on opposite sides of the bolster.

For a more complete disclosure of the braking mechanism described, reference is made to the aforesaid Busch Patent No. 2,903,096.

The wheel and brake disc unit 16 comprises the car Wheel 13 and the friction brake disc 15 coaxial therewith and disposed on the inner or inboard side of the wheel, as already described. The car wheel 13 comprises a hub embracing the corresponding axle 12 and keyed, pressed and/ or otherwise aflixed thereto for rotation therewith in any suitable manner. The brake disc 15 is circular and comprises an annular web 36 with an inner annular marginal section 37 forming a hub for said disc and embracing the corresponding axle with a press-fit or with merely a snug fit, and an outer annular marginal section 38 offset axially from the plane of said hub section in an inboard direction and presenting an annular flat braking surface 40 against which the braking shoes 21 are applied for braking action. The brake disc 15 is rigidly and removably secured to the corresponding wheel 13 for rotation therewith by means of studs (not shown) passing through holes 41in the brake disc hub 37 and threaded into the wheel hub 35.

The brake disc 15 is ofsectionalized construction to permit the easy removal of the disc from the cor-responding axle 12 and its replacement thereon without the need of disassemblying the car truck, and to permitthe replacement of only one section of the brake disc when said section is broken or otherwise damaged. For that purpose, the brake disc 15 comprises two identical disc halve segments 44, each encompassing an angle of 180 and each formed on one radial side edge with a tubular projection in the form of a knuckle, overhanging said side edge to form an axially facing shoulder 48, and formed on the other radial side edge with two spaced tubular projections 46, also in the form of knuckles, overhanging the latter edge to form respective axially facing shoulders 49. The single projection 45 on one disc segment 44 is complemental to the two projections 46 on the other disc segment 44 and when the two disc segments are together, the projections 45 and 46 on the two disc sections intermate to form knuckle joints on diametrically opposite sides of the composite brake disc. Bolts 47 passing through these knuckle joints removably connect the two segments 44 of the disc together.

It should be noted that when the two disc segments 44 are connected together by means of the bolts 47, the two radial side edges of the two segments on each side of the disc are in or close to abutting relationship, while the knuckles 45 and 46 on each segment are shouldered against the face of the other segment through the shoulders 48 and 49 on these knuckles, as shown in FIGS. 5, 6 and 7. By means of this shouldering and abutting intermeshing relationship between the sides of the brake disc segments 44, and by means of .the direct interconnection of the segments through the knuckle joints and the bolts 47 passing therethrough, the two segments will not only be interlocked against relative axial displacement but also against relative angular movements about the longitudinal axis of the bolts 47. Therefore, any pressure applied to any brake disc segment 44 by the application of braking pressure thereto in an axial direction, will be transmitted directly to the other segments, and success-fully resisted without depending entirely on the studs which pass through the holes 41 in the brake disc 15 to attach the brake disc to the corresponding wheel 13.

As a feature of the present invention, the brake disc 15 has integral with the web 36 a series of fins 50 on the side thereof opposite the braking surface 49 on its outer marginal section 38, designed to induce air flow across the face of said outer marginal disc section 38, when the disc 15 is rotating in one direction, and a series of fins 51 on the same side of the web 36 and also on the outer marginal section 38, designed to induce air flow across the face of said outer marginal disc section 38, when the disc 15 is rotating in the other direction. The fins 50 and 51 thereby function as air vanes.

For the purpose described, each vane 50 is substantially arcuately curved for a major section 52 of its length about a center A on a circumferential line B located substantially midway between the outer end of the vane 50 at the outer rim of the web 36 and the inner end of its major section 52, and is offset near its radially inner end with streamline curvature to form a substantially radially extending inner section 53. Each vane 51 is similarly curved but in opposite direction to define a major arcuate section 54 and a substantially radially extending inner section 55.

In a specific embodiment of the invention, the vanes 50 and 51 can be five and one-half (5 /2) inches long in a radial direction, the centers A of curvature of the major arcuate sections 52 and 54 may be located on a circumferential line B located two inches inwardly from the outer rim of the web 36 and the radius R of these major sections 52 and 54 to their concave facesmay be three and nine-sixteenth (3% inches.

The vanes 50 and 51 are arranged alternately around the circumference of the disc 15 so that they are arranged in pairs, the fins 5t and 51 in each pair having their major concave sides facing each other. Disposed midway between adjoining pairs of vanes 50 and 51 are short radial fins 57 near the outer sections of these vanes and short radial fins 58 near the inner sections of the vanes. These short fins 57 and 58 serve as stiffeners for the web 36 and also assist in dissipating the heat generated. Also, midway between the vanes 50 and 51 of each pair of vanes having confronting concave faces is a radial fin 60 spaced at its outer end inwardly from the outer rim of the web 36 and spaced at its inner end outwardly from the circumferential line of the inner ends of the vanes 50' and 51. These radial fins 60 serve as stifieners for the web 36 and also assist in dissipating heat.

In the operation of the brake disc -15, after the brakes have been released from the frictionally heated brake disc, and the railway car has resumed its movement, and assuming that the brake disc is rotating clockwise (FIGS. 2 and 3), the vanes 50 will suck in air at their outer ends, will draw the air in a generally radially inward direction along said vanes, along the radial fins 60 and along the face of the web 36 opposite the braking face 40, and will discharge said air in a radial direction from the inner ends of the vanes. The air so induced along these vanes 50 and along the face of the web 36 will cool these parts. Assuming that the brake disc 15 is rotating counterclockwise (FIGS. 2 and 3), the vanes 51 will similarly induce circulation of air along the vanes 51, along the radial fins 60 and along the face of the web 36 opposite the braking face 40 and will discharge said air in a radial direction from the inner ends of the vanes, thereby cooling these parts with which the induced air comes into contact. The brake disc 15 is thereby eifectively cooled between braking intervals, and this action is highly advantageous, especially where there is frequent braking action.

The brake disc 15 is so designed that it can be economically manufactured as a casting, forging, pressing or the like in one piece.

While the invention has been described with particular reference to a specific embodiment, it is to be understood that it is not to be limited thereto but is to be construed broadly and restricted solely by the scope of the appended claims.

What is claimed is:

1. A brake disc for a car wheel of a railway car truck, said brake disc comprising an annular web divided into similar interchangeable segmental sections, means releasably securing said sections together, said web presenting a braking face on one side, and two series of vanes on the face of said web opposite the braking face, integral with said web and spaced circumferentially along said web, the vanes of the two series being curved in opposite directions, one series of vanes having their concave faces facing one circumferential direction of the disc and the other series of vanes having their concave faces facing the opposite circumferential direction of the disc, the vanes in the two series alternating along the circumference of the web.

2. A brake disc as described in claim 1, said web also having integral therewith radially extending heat dissipating and web reinforcing fins on the side of said web opposite the braking face extending between adjoining vanes, one fin extending midway between each pair of adjoining vanes having confronting concave faces, and one fin extending midway between each pair of adjoining vanes having confronting convex faces.

3. A brake disc as described in claim 1, the fin extending midway between the convex faces of each pair of adjoining vanes being located near the radially outer region of the web, said web also having integral therewith on the side of said web opposite the braking face a heat dissipating and web reinforcing fin extending midway between each pair of adjoining vanes having confronting convex faces, the latter fin being located near the radially inner region of the Web.

4. A brake disc for a car wheel of a railway car truck, said brake disc comprising an annular web presenting a braking face on one side, and two series of vanes rigidly extending from and spaced circumferentially along the face of said web on the opposite side, the vanes of one series being contoured to induce circulation of air along the vanes of said one series and across the face of the web on said opposite side, as said brake disc rotates in one direction, the vanes of the other series being contoured to induce circulation of air along the vanes of said other series and across the face of the web on said opposite side, as said brake disc rotates in the opposite direction, the vanes of the two series being curved in opposite directions, one series of vanes having their concave faces facing one circumferential direction of the disc and the other series of vanes having their concave faces facing the opposite circumferential direction of the disc.

5. A brake disc as described .in claim 4, the vanes in the two series alternating along the circumference of the web.

6. A brake disc as described in claim 4, said vanes being integral with said web, said web also having integral therewith heat dissipating and web reinforcing fins on the side of said web opposite the braking face, located between vanes.

References Cited by the Examiner UNITED STATES PATENTS 1,767,309 6/1930 Ricardo 192'1 13 2,345,016 3/1944 Tack 188-218 2,869,688 1/1959 Busch 188-218 FOREIGN PATENTS 1,038,593 9/1958 Germany.

871,861 7/1961 Great Britain.

MILTON BUOHLER, Primary Examiner. FERGUS S. MIDDLETON, Examiner.

G. E. A. HALVOSA, Assistant Examiner. 

1. A BRAKE DISC FOR A CAR WHEEL OF A RAILWAY CAR TRUCK, SAID BRAKE DISC COMPRISING AN ANNULAR WEB DIVIDED INTO SIMILAR INTERCHANGEABLE SEGMENTAL SECTIONS, MEANS RELEASABLY SECURING SAID SECTIONS TOGETHER, SAID WEB PRESENTING A BRAKING FACE ON ONE SIDE, AND TWO SERIES OF VANES ON THE FACE OF SAID WEB OPPOSITE THE BRAKING FACE, INTEGRAL WITH SAID WEB AND SPACED CIRCUMFERENTIALLY ALONG SAID WEB, THE VANES OF THE TWO SERIES BEING CURVED IN OPPOSITE DIRECTIONS, ONE SERIES OF VANES HAVING THEIR CONCAVE FACES FACING ONE CIRCUMFERENTIAL DIRECTION OF THE DISC AND THE OTHER SERIES OF VANES HAVING THEIR CONCAVE FACES FACING THE OPPOSITE CIRCUMFERENTIAL DIRECTION OF THE DISC, THE VANES IN THE TWO SERIES ALTERNATING ALONG THE CIRCUMFERENCE OF THE WEB. 